Stitched fiber-reinforced substrate material, preform material, fiber-reinforced composite material, and production method for same

Abstract

An object of the present invention is to provide a stitched fiber-reinforced substrate material capable of suppressing the formation of microcracks in a fiber reinforced composite material. The stitched fiber-reinforced substrate material of the present invention is a stitched fiber-reinforced substrate material formed by stitching reinforcement fiber sheets made of reinforcement fibers using stitching yarns that exhibit an in-plane shear strength transition rate of 5% or more. The stitching yarn is preferably adhered by an organic compound having a polar group.

1 . A stitched fiber-reinforced substrate material formed by stitching reinforcement fiber sheets made of reinforcement fibers using stitching yarns,
 the stitching yarn being a stitching yarn exhibiting an in-plane shear strength transition rate of 5% or more.   
     
     
         2 . The stitched fiber-reinforced substrate material according to  claim 1 , wherein the reinforcement fiber sheet is a reinforcement fiber sheet made of unidirectionally drawn and aligned reinforcement fiber. 
     
     
         3 . The stitched fiber-reinforced substrate material according to  claim 1 , wherein the reinforcement fiber sheet is formed by laminating a reinforcement fiber sheet made of unidirectionally drawn and aligned reinforcement fiber layer by layer by altering the fiber axial direction. 
     
     
         4 . The stitched fiber-reinforced substrate material according to  claim 1 , wherein the stitching yarn has a linear expansion coefficient in the fiber axial direction of −1×10−6 to 70×10−6/K after heated at 180° C. for 2 hours and then cooled. 
     
     
         5 . The stitched fiber-reinforced substrate material according to  claim 1 , wherein the stitching yarn is a stitching yarn to which an organic compound having a polar group is adhered. 
     
     
         6 . A method for manufacturing a stitched fiber-reinforced substrate material, comprising:
 stitching a reinforcement fiber sheet made of reinforcement fiber using stitching yarns exhibiting an in-plane shear strength transition rate of 5% or more as measured by the method described in the DESCRIPTION.   
     
     
         7 . A preform material comprising: the stitched fiber-reinforced substrate material according to  claim 1  and a binder resin of 1 to 20 parts by mass with respect to 100 parts by mass of the stitched fiber-reinforced substrate material. 
     
     
         8 . A method for manufacturing a preform material comprising: heating the stitched fiber-reinforced substrate material according to  claim 1  and a binder resin under pressure. 
     
     
         9 . A fiber reinforced composite material comprising: the stitched fiber-reinforced substrate material according to  claim 1  and a matrix resin formulation of 20 to 60 parts by mass with respect to 100 parts by mass of the stitched fiber-reinforced substrate material. 
     
     
         10 . A method for manufacturing a fiber reinforced composite material comprising:
 impregnating a matrix resin into the stitched fiber-reinforced substrate material according to  claim 1 .   
     
     
         11 . The stitched fiber-reinforced substrate material according to  claim 2 , wherein the reinforcement fiber sheet is formed by laminating a reinforcement fiber sheet made of unidirectionally drawn and aligned reinforcement fiber layer by layer by altering the fiber axial direction.